1. Field of the Invention
The present invention relates to railway freight cars and more particularly to open top gondola cars particularly suited for high speed unit train operations.
2. Description of the Prior Art
As discussed in U.S. Pat. No. 4,024,821 issued May 24, 1977 to Tunghan Yang which is incorporated by reference herein, because of their high side and end wall constructions, high volume gondola cars are less rigid against torsion and therefore vulnerable to severe end-to-end torsional twisting as well as surge loading by the cargo bulk. For this reason, experience has shown that during rail use over rough or high speed tracks, generally oscillatory end-to-end torsional loading on the gondola causes simultaneous lateral and longitudinal oscillatory deflection of the upper portions of the car walls which necessarily dictates and limits the operating speed of the train.
The application cited above discloses a gondola car reinforcing means comprising a pair of crossed diagonal braces which extend downwardly longitudinally inward and substantially laterally across therewithin. Attention is also directed to U.S. Pat. Nos. 2,033,566; 2,146,221 and 2,464,080 which show diagonal bracing extending normal to the wall of a railway car. U.S. Pat. Nos. 789,854 and 1,262,301 show crossbracing parallel to the end wall of a car and coupled to the outboard portions of the car. None, however, solve the problem of rigidifying the car body by diagonal braces which bisect the corners of the car and dump the pulsating car wall deflection loads and vibrations into the minimum vertical flexure portions of the car to effectively resist destructive flexure of the car walls while minimizing structurally fatiguing car body vibrations initiated by the pulsating car wall deflection loads.